Method and machine for fashioning sheet materials

ABSTRACT

A method and machine for fashioning pleated and also chevronpatterned structures. Crease lines may be marked on a continuously unwinding sheet material, which is propelled in a direction approaching a forming structure at a speed in excess of the speed of withdrawal of said structure. The pleats are received between the teeth of a rake assembly associated with forming heads position on either side of the path of the sheet or strip, at the entrance to receiving tunnel which is moved alternately from one head to the other so as to cause the strip to move cyclically toward and away from each rake.

United States Patent [191 Auer May 27, 1975 [54] METHOD AND MACHINE FOR 1,546,195 7/1925 Briskin 72/187 1,849,944 3/l932 Medville 72/187 FASHIONING SHEET MATERIAITS 3,641,803 2/1972 Schuurbiers et al. 72/187 [75] lnventor: Wolf Maria Auer, Schmrden bei Stuttgart Germany Primary Examiner-C. W. Lanham [73] Assignee: Bremsen-und-Filter- Assistant Examiner-James R. Duzan Handelsgesellschaft mbH, Stuttgart, Attorney, Agent, or F [rm-Murray Schaffer Germany [22] Filed: May 7, 1973 [57] ABSTRACT [21] Appl. No.: 357,916 A method and machine for fashioning pleated and also chevron-patterned structures. Crease lines may be marked on a Continuously unwinding sheet material, [30] Forelgn Apphcauon Pmmty Daw which is propelled in a direction approaching a form- May 19, France Structure at a Speed in excess of the speed of with drawal of said structure. The pleats are received be- U-S. tween the teeth of a rake assembly associated hit. forming heads position on either i f the p of [58] held of Search 72/385 113/1 the sheet or strip, at the entrance to receiving tunnel 1 13/118 C which is moved alternately from one head to the other so as to cause the strip to move cyclically toward and [56] References Cited away from each rake UNITED STATES PATENTS 1,098,144 5/1914 Baumgartner 72/187 16 Clam, 6 Drawmg Figures II? F 25 23 2 Y 1H 29 g7 T 34 -rs.\

H I i! 7 E a lllllllll lllllllllllflllillll llll IiilllllilllllllllllllllllllllllllllllllllllllllllllllIllllllllllllllllllllllllllllllllllll'llllllli ill PATENTEBMAY 27 1975 SHEET smvg m mm 3 w whi MHUU w 3cm. mm 3? Q mw WEE METHOD AND MACHINE FOR F ASHIONING SHEET MATERIALS viding crease lines on the sheet at the locations of the pleats and/or chevrons and thereafter causing the sheet to pass between two master-sheet formers, but this method has the disadvantage of being slow to carry out and of being poorly adaptable to non-continuous operation.

In this latter-mentioned method, the means which support the forming heads are heavy and the inertia of the different parts prevents the mechanisms from being driven at high speeds, thereby necessarily limiting the output of each machine.

Other techniques have been developed for forming,

from continuously unwinding strips or hands, pleated and/or chevron-patterned structures, which techniques involve marking pleat and/or chevron creases on the flat strip and, by simultaneously thrusting and guiding the strip along a path which accentuates the formation of the pleats and/or chevrons. The major disadvantage of these techniques stems from the complexity of the mechanisms needed to guide the strips so that the ultimate structure assumes its pleated and/or chevron pattern without the creation of any appreciable tension capable of tearing the material or locally deforming the structure. It is the principal object of this invention to remedy these latter-mentioned techniques by permitting nonstop in-process formation and accentuation of the pleating, or formation and accentuation of the chevron pattern, on continuously supplied strip material, and thereafter withdrawal of the ultimate structure which may be either merely pleated or be both pleated and chevron-patterned. The invention accordingly relates to a method of obtaining pleated and/or chevronpatterned structures from strip material, comprising in combination, the phases of marking pleat and chevron crease lines on the strip, impelling the creased strip to forming means which assist formation of the pleats and chevrons, by feeding the strip at a speed higher than that at which the pleated structure is withdrawn, offering the pleats or chevrons alternately to the fashioning members of the forming means positioned on either side of the strip path, in such manner that engagement into one of said members immediately succeeds disengagement from the opposite companion member, responsive to a phase of transverse displacement of the structure obtained as the latter is being discharged.

In one specific example of performance of such method, accentuation of the pleating is obtained by successive progressive tightenings of the pleats.

Similarly, accentuation of the chevron pattern is obtained by pushing against the chevron peaks and restraining the chevron troughs, the successive projections and troughs being considered in the direction of travel of the structure undergoing formation. The said pushing and restraining is obtained respectively by continuously and alternately increasing and reducing the rates of displacement of said projections and troughs.

In such cases it is furthermore possible to accentuate the chevron pattern by a transverse compression of the structure being completed as the same travels towards its discharge point.

The present invention further relates to apparatus for performing such method, which comprises a machine having marking and driving rollers and by the provision, downstream of the rollers, of an oscillating tunnel for receiving the formed structure. The tunnel has a profiled entrance and is movable pendularly between two opposite forming heads each of which has a series of rakes having the same degree of convergence as the tunnel when same has a convergent configuration. These rakes are formed with teeth, the spacing between which, increases in the downstream direction, and each rake is connected with an advancing and retracting mechanism in the associated head.

Alternate rakes of each head have a more rapid advance than their companion rakes, the fastest rake tending to push the peak region of a chevron while the slowest has a restraining effect on the adjacent trough line.

The movements of the rakes in the two opposed heads are preferably coordinated by interconnecting the two series of rakes by means of a rocker which actuates eccentric shafts which are oppositely orientated for any pair of companion rakes, the eccentric shafts engaging into the ends of said rocker by means of terminal blocks on the shafts carried in terminal forks of the rocker arms.

It is likewise preferable to coordinate the motion of the rocker with the pendular motion of the tunnel from a single prime mover having an eccentric and a cam.

Coordination of these motions may besuch that the rocker be actuated when, in the course of its motion, the tunnel activates a limit stop.

The flanks of the tunnel are provided with racks, each separated into stationary restraining elements, and moving pusher elements possessed of motion in concert with that of the tunnel which will move the strip.

Further, a single drive taken off a motor/reduction gear unit provides synchronization of the motions of the tunnel, the rocker, the rakes, the racks and the marking and propelling rollers.

It is possible with such means to obtain a continuous operation with great efficiency and from smooth sheet material, pleated and chevron-patterned structures which may particularly be employed for fluid filtering applications, and most notably .for use in the motor industry and in the fields of air and lubricant filtering in heat engines, for which mass production is necessary.

As described in French Pat. No. 1.440.725, the strip material can be'arranged in at least two thicknesses at the entrance end to the machine whereby to be formed into asymmetrical folds. These strips can have an intermediate band placed between them whereby to accentuate said asymmetry.

The description which follows with reference to the accompanying non-limitative exemplary drawings will give a clear understanding of how the invention can be carried into practice.

In the drawings:

FIG. 1 shows in longitudinal section through the line II of FIG. 2 a machine for manufacturing a pleated and chevron-patterned structure from strip material;

FIG. 2 is a section through the line IIII of FIG. 1;

FIGS. 3, 4 and are sectional views through the lines III-III, IVIV and VV of FIG. 1; and

FIG. 6 shows on an enlarged scale the arrangement, in a forming head, of the interconnection between rakes, actuating eccentrics and rocker ends.

In the illustrated exemplary embodiment, a machine according to this invention includes a base 1 which houses bearings for which compressing, marking and propelling rollers 2 and 3 are journalled. The rollers operate on continuous strip material 4 propelled from a magazine (not shown) towards an outlet for the fashioned structures. This base also supports a motor/reduction gear unit 5 which through a desmodromic drive 6 rotates a pulley 7 fixed fast with roller 3. The base 1 further supports sidewalls or flanks 8 which carry a shaft 9 for a cam and eccentric and having a pulley 10 over which the drive means 6 runs. An extension of the flanks 8 opposite the motor unit supports trunnions 11 about which is oscillatably mounted a tunnel 12. The flanks 8 further support trunnions 13 for a rocker frame 14 which is attached to a spring 15 adjustably secured to a cross-member 15a forming a spacer between the extensions of said flanks.

Shaft 9 is fixed fast with an eccentric block 16 the linkshaped cage 17 of which is attached to a pin 18 fast with a cross-member 19 of the tunnel 12. Shaft 9 is also fast with a cam 20 which cooperates with a follower 21 supported on a crosspiece for actuating the rocker 14 of which a cross-member 22 is part.

On either side of the space within which the end of tunnel 12 is movable, the flanks 8 support two opposed forming heads 23 and 24 fast therewith. Mounted in these grooved heads is a plurality of facing rakes 25 and 26 each having a row of teeth of substantially constant height, with the exception of the first entry tooth which is lower and more rounded than the others, the pitch of the teeth in said rows decreasing in the downstream direction. The sets of rakes 25 and 26 are movable and are mutually converging to a slight degree.

These rakes are slidably mounted in their respective slots in heads 23 and 24 by attachment means provided in each head by a forward transverse rod 27 (or 28) extending through a longitudinal mortise in each rake and by virtue of the latter being mounted, opposite said rods, on eccentric blocks 29 and 30 forming part of pins 31 and 32 the ends of which are rotatable in lateral bearings 33 engaging into an indent 34 in each head, the ends of said pins being formed with flat portions 35 slidably mounted in forks 36 and mortises 37 of the rocker arms.

On the same side as rollers 2 and 3, the tunnel assembly 12 is formed at its end with a profiled mouth 38. In the region of heads 23 and 24, tunnel 12 includes flanks 39 which converge in the downstream direction. Formed in the upper and lower faces are slots 40 for passage of each of the rakes 25 and 26, said flanks and said slots having the same degree of convergence.

Downstream of this convergent region, the lateral faces of the tunnel are provided with racks each of which consists of two fixed elements 41 and 42 on either side of a movable slide 43. Slide 43 is restrained at the outer end of the tunnel, adjacent the trunnions 11, by a peg 44 which is inserted into a perforation in tunnel member 12 and the tip of which inserted into a mortise formed in said slide, in the face thereof behind the toothed face. On the opposite side, each slide is fast with a peg 45 inserted into a mortise 46 in the tunnel flank, which peg terminates in a nipple 47 cooperating with a symmetrical arcuate mortise 48 formed in a fitted plate 49 which is provided on each side and secured to the corresponding flank 8.

On a given shaft 31, for example, the eccentric blocks 29 are alternately set out of phase by half a turn, such that when shaft 31 advances responsively to rocker 14 there occurs a rotation of the block 29 as a result of engagement of the flats 35 with the forks 36 and a complementary advance of the lateral and central rakes 25, whereas the possible advance authorized for the two intermediate rakes, the eccentric blocks of which are set out of phase by is reduced.

The central rake and the lateral rakes (in the case of a structure with a two-chevrons pattern, say) provide a dorsal entrainment of the chevron peaks whereas the intermediate rakes provide a restraining effect on the two chevron troughs. Thus the rakes are caused to act differently in respect of chevron peaks and chevron troughs.

A machine as hereinbefore described operates in the following manner:

In response to the drive exerted, rollers 2 and 3 cause the strip 4 to advance simultaneously impressing thereon, for example, a pattern of mutually adjoining parallelograms. The relief pattern is reversed from one imprint line to the next or to the adjoining imprint line, that is to say that it appears alternately on the two sides of strip 4.

The strip impressed thus is propelled towards the two heads 23 and 24, and because this strip moves towards an already formed pleated structure, moving at a much slower speed than the speed at which the strip is being propelled, the latter becomes pleated. When the structure already formed in tunnel 12 moves downwardly with the motion of the tunnel, the pleat caused by said propulsion engages into the first tooth gap on the lower rakes 26. As shown in FIG. 1, these lower rakes lie advanced in the downstream direction towards the discharge end of the machine.

By reason of the concerted rotation of the shaft 9, tunnel 12 rises once more and thereby tends to disengage the pleat from this tooth gap, which pleat is meanwhile being tightened to a degree dependent on the rate of continuous advance of strip 4.

In the intermediate situation, this pleat escapes from lower rakes 26, and the previous pleat of opposite sense engages into the next tooth gap (i.e., the second gap from the upstream end) in the upper rakes 25. The above-indicated motions of the pleats are assisted by the retracted position then occupied by the rakes 25.

As the tunnel continues to rise responsively to eccentric 16, 17 actuated by shaft 9, this initial pleat engages fully, as it tightens, into the narrower profile of this second tooth of rakes 25.

Meanwhile, the output from the rollers causes the next pleat to engage into the initial wide teeth of rakes 25.

Once it has engaged into the second teeth of rakes 25, the initial pleat is thrust downstream by the forward motion then generated through cooperation between cam 20, follower 21, rocker 14, forks 36, flats 35 and pin 34 producing the sliding motion of said rakes.

Thus all these movements are repeated at each beat of tunnel 12 and at each oscillation of rocker 14 and rakes 25 and 26 whereby to obtain a tight structure of pleats'which crowd into tunnel 12, through which progression of the pleated structure results from the marginal cooperation thereof with the teeth of the fixed restraining racks 41 and the movable propelling racks 43, which racks are moved back and forth twice for each tunnelbeat through cooperation of pegs and their nipples 47 with mortises 48.

The action of pleating, of accentuating the tightness of the pleats and of finally juxtaposing the pleats over the entire discharge region of tunnel 12 can be coordinated with the formation of chevrons. To each upper rake 25 and facing lower rake there corresponds either a chevron peak or a trough between two adjacent chevrons. In the exemplary embodiment considered herein, in which each head has five associated rakes, the two outer rakes and the central rake correspond to chevron peaks whereas the two intermediate rakes correspond to chevron troughs.

Because the eccentric blocks 29 are mutually outphased by 180 from one to the next, it will readily be appreciated that the motion of rocker 14 is accompanied by rotation of the eccentric blocks responsively to the co-acting of forks 36 with flats 35 and of the corresponding mortises 37 with the companion flats on shaft 32.

The external blocks and the central block thus cause their associated rakes to be advanced lengthwise within the heads to a greater extent downstream than the intermediate rakes. The latter restrain the chevron troughs with the back of their teeth whereas the external rakes and the central rake push the chevron peaks further forward with the front of their teeth.

The initial result of this is an appropriate positioning of the chevron peaks and a slight tendency to accentuate the chevron pattern. This tendency is further enhanced by the narrowing of the passageway through the converging portion of the tunnel entrance, upstream of the parallel flanks of the tunnel exit region where the restraining and propelling racks operate.

It is possible with the abovedescribed means to obtain a high output of pleated and possibly chevronpatterned structures of perfect uniformity, without any tendency for the strip material to tear since it is handled progressively, thus enabling the use even of delicate materials.

The energies developed by the moving parts of the machine are low since the massive components remain stationary and the moving parts are of light weight.

Indeed the output rates can be such that instead of using an ordinary cam with a lobe 20, in association with the spring 15, it may prove necessary to employ a grooved cam or any other convenient desmodromic control means in order to avoid any tendency for follower 21 to float.

It goes without saying that changes and substitutions may be made to the forms of embodiment hereinbefore described, without departing from the scope of the invention. For instance, if no chevron pattern is to be imparted, relative motion of the rakes is dispensed with.

Whatwe claim is:

l. A method for pleating or forming chevron patterns on strip sheet material comprising the steps of continually pushing an elongated strip between a pair of op posed forming heads, each having a rake shaping member, cyclically moving said rake shaping members on opposite sides of said strip to engage said strip and form transverse pleats, the rakes of said shaping members having a plurality teeth to engage said strip arranged in alternate opposition to each other and progressively decreasing in pitch in the direction of movement of said strip, withdrawing the lead endof said strip from said rake shaping members and simultaneously moving said strip cyclically toward and away from each of said rake shaping members causing the engagement of said strip into the teeth of one of the opposed shaping members immediately succeeding disengagement from the immediately preceding teeth of the other rake shaping member so as to progressively form said strip into tighter pleats.

2. The method according to claim 1 including the step of receiving the leading end of said strip and moving said strip pivotally from one rake shaping member to the other to alternately disengage said strip from one of said rake shaping members and engage it in the other of said rake members, and retarding the forward movement of said strip to complete said pleating.

3. The method according to claim 2 wherein said rake shaping members are synchronously reciprocated in an alternate cyclical motion generally parallel to each other, the thrust of said motion on the rear of each pleat being formed in said strip being at a continuously increasing speed and the thrust of said motion on the front of each pleat being formed in said strip being at a continuously decreasing speed.

4. The method according to claim 2 including the step of compressing the strip transversely of its length simultaneously with its withdrawal to retard the forward movement thereof.

5. The method according to claim 1 including the step of simultaneously feeding at least two superimposed strips to said opposing rake members.

6. The method according to claim 1 including the step of scoring said strip material corresponding to the fold lines of the pleats to be formed prior to passage of said strip through the opposing rake members.

7. Apparatus for forming pleated and chevron patterns in fiat strip material comprising a pair of oppositely arranged forming heads, each having a rake shaping member comprising a plurality of longitudinally spaced groups of teeth, said groups being disposed in a series of teeth disposed longitudinally and converging in the longitudinal direction, the distance between successively adjacent teeth in each group decreasing in the longitudinal direction, means for continually feeding strip material between said forming heads, means for cyclically moving said strip material toward each rake member alternately to cause said teeth to bend said moving strip material, means for simultaneously withdrawing the leading end of said moving strip of material from between said rake members after the formation of each bend, said withdrawing means being swingable synchronously within the space between said rake members to engage and disengage said sheet material successively alternately in and from the teeth of said opposing rake members, said rake members being arranged so that the bends in said sheet material alternately engage within the successive teeth of the opposite rake member immediately on disengagement from the opposite one, to thereby index the movement of said strip material through said teeth to form progressively tighter bends.

8. The apparatus according to claim 7 wherein said means for withdrawing said strip comprises an elongated tunnel having one end adjacent said forming heads and another end remote therefrom from discharging said bent strip, said one end having an intake portion for holding said strip and being profiled to retard the forward movement of said strip, and means for pendulously oscillating at least said intake end from one of said rake members to the other to alternately lodge and dislodge said strip in and from said rake members.

9. The apparatus according to claim 8 wherein the one end adjacent the forming heads is provided with slots for penetration thereinto of the opposing teeth of said rake members.

10. The apparatus according to claim 7 wherein said means for cyclically moving the series of teeth of said rake members superimposing a movement advancing and retracting each of said series of teeth relative to the direction of movement of said strip material, alternately increasing the speed of advance and decreasing the speed of retraction applied to each series of teeth.

11. The apparatus according to claim 7 wherein said means for feeding said strip material comprises a pair of rollers located upstream of said rake members, said rollers having means for impressing score lines on said strip corresponding to the folds of said pleats.

12. The apparatus according to claim 8 wherein the means for moving said rake members and for pivoting said tunnel comprises an eccentric and cam mechanism rotatable about common axis, and includes an articulated connection between said eccentric and said tunnel, a cam follower, a rocker arm connected at one end to said cam follower and at the other end articulatingly connected to each of said series of teeth, said series of teeth being mounted on an eccentric shaft and slide bearings.

13. The apparatus according to claim 12 including a common drive means for rotating said strip material, feed rollers and the eccentric and cam mechanism for pivoting said tunnel.

14. The apparatus according to claim 13 wherein said eccentric and articulated connection to said tunnel provides an intermittant motion and said cam is so profiled in relation to said eccentric as to cause the motion of said rake members to occur during the interval between alternate swing of said tunnel.

15. The apparatus according to claim 14 wherein said series of teeth and the one end of said tunnel adjacent thereto have the same degree of convergence.

16. The apparatus according to claim 8 wherein the side walls of at least the one end of said tunnel adjacent said rake members is provided with an elongated rack, and means associated with said rack reciprocably movable along the direction of movement of said strip material received therein to advance said strip material along said rack, and means for actuating said means for advancing said strip material cooperatively with the swinging of said tunnel. 

1. A method for pleating or forming chevron patterns on strip sheet material comprising the steps of continually pushing an elongated strip between a pair of opposed forming heads, each having a rake shaping member, cyclically moving said rake shaping members on opposite sides of said strip to engage said strip and form transverse pleats, the rakes of said shaping members having a plurality teeth to engage said strip arranged in alternate opposition to each other and progressively decreasing in pitch in the direction of movement of said strip, withdrawing the lead end of said strip from said rake shaping members and simultaneously moving said strip cyclically toward and away from each of said rake shaping members causing the engagement of said strip into the teeth of one of the opposed shaping members immediately succeeding disengagement from the immediately preceding teeth of the other rake shaping member so as to progressively form said strip into tighter pleats.
 2. The method according to claim 1 including the step of receiving the leading end of said strip and moving said strip pivotally from one rake shaping member to the other to alternately disengage said strip from one of said rake shaping members and engage it in the other of said rake members, and retarding the forward movement of said strip to complete said pleating.
 3. The method according to claim 2 wherein said rake shaping members are synchronously reciprocated in an alternate cyclical motion generally parallel to each other, the thrust of said motion on the rear of each pleat being formed in said strip being at a continuously increasing speed and the thrust of said motion on the front of each pleat being formed in said strip being at a continuously decreasing speed.
 4. The method according to claim 2 including the step of compressing the strip transversely of its length simultaneously with its withdrawal to retard the forward movement thereof.
 5. The method according to claim 1 including the step of simultaneously feeding at least two super-imposed strips to said opposing rake members.
 6. The method according to claim 1 including the step of scoring said strip material corresponding to the fold lines of the pleats to be formed prior to passage of said strip through the opposIng rake members.
 7. Apparatus for forming pleated and chevron patterns in flat strip material comprising a pair of oppositely arranged forming heads, each having a rake shaping member comprising a plurality of longitudinally spaced groups of teeth, said groups being disposed in a series of teeth disposed longitudinally and converging in the longitudinal direction, the distance between successively adjacent teeth in each group decreasing in the longitudinal direction, means for continually feeding strip material between said forming heads, means for cyclically moving said strip material toward each rake member alternately to cause said teeth to bend said moving strip material, means for simultaneously withdrawing the leading end of said moving strip of material from between said rake members after the formation of each bend, said withdrawing means being swingable synchronously within the space between said rake members to engage and disengage said sheet material successively alternately in and from the teeth of said opposing rake members, said rake members being arranged so that the bends in said sheet material alternately engage within the successive teeth of the opposite rake member immediately on disengagement from the opposite one, to thereby index the movement of said strip material through said teeth to form progressively tighter bends.
 8. The apparatus according to claim 7 wherein said means for withdrawing said strip comprises an elongated tunnel having one end adjacent said forming heads and another end remote therefrom from discharging said bent strip, said one end having an intake portion for holding said strip and being profiled to retard the forward movement of said strip, and means for pendulously oscillating at least said intake end from one of said rake members to the other to alternately lodge and dislodge said strip in and from said rake members.
 9. The apparatus according to claim 8 wherein the one end adjacent the forming heads is provided with slots for penetration thereinto of the opposing teeth of said rake members.
 10. The apparatus according to claim 7 wherein said means for cyclically moving the series of teeth of said rake members superimposing a movement advancing and retracting each of said series of teeth relative to the direction of movement of said strip material, alternately increasing the speed of advance and decreasing the speed of retraction applied to each series of teeth.
 11. The apparatus according to claim 7 wherein said means for feeding said strip material comprises a pair of rollers located upstream of said rake members, said rollers having means for impressing score lines on said strip corresponding to the folds of said pleats.
 12. The apparatus according to claim 8 wherein the means for moving said rake members and for pivoting said tunnel comprises an eccentric and cam mechanism rotatable about common axis, and includes an articulated connection between said eccentric and said tunnel, a cam follower, a rocker arm connected at one end to said cam follower and at the other end articulatingly connected to each of said series of teeth, said series of teeth being mounted on an eccentric shaft and slide bearings.
 13. The apparatus according to claim 12 including a common drive means for rotating said strip material, feed rollers and the eccentric and cam mechanism for pivoting said tunnel.
 14. The apparatus according to claim 13 wherein said eccentric and articulated connection to said tunnel provides an intermittant motion and said cam is so profiled in relation to said eccentric as to cause the motion of said rake members to occur during the interval between alternate swing of said tunnel.
 15. The apparatus according to claim 14 wherein said series of teeth and the one end of said tunnel adjacent thereto have the same degree of convergence.
 16. The apparatus according to claim 8 wherein the side walls of at least the one end of said tunnel adjacent said rake members is provided with an elongated rack, anD means associated with said rack reciprocably movable along the direction of movement of said strip material received therein to advance said strip material along said rack, and means for actuating said means for advancing said strip material cooperatively with the swinging of said tunnel. 